<span>C. New substances are always produced in chemical changes, which is not the case with physical changes. For example, when you cut wood into smaller pieces you still have wood in the end. But, with a chemical change you change the substance's whole composition. For example when you add two hydrogen's to one oxygen you have water and it can't break down from that. </span><span />
Answer:
6e⁻
Explanation:
Charge in reducing 2 mole of Cr⁶⁺ to Cr³⁺
Cr⁶⁺ + xe⁻ → Cr³⁺
The numbers 6+ and 3+ on the chromium atoms are the oxidation number of the atom.
It shows the number of electrons that has been lost by chromium in an oxidation state.
Cr⁶⁺ shows that it has lost 6 electrons. When an atom loses electrons, the number of protons becomes more. This makes it positively charged in nature.
This analogy goes for Cr³⁺
Therefore, in going from reactants to products, chromium
6+ → 3+
In this kind of expression, the number of atoms must be conserved and the charges too;
2Cr⁶⁺ + xe⁻ → 2Cr³⁺
given 2 moles of Cr;
To balance the charge;
2(6+) + x(-) = 2(3+)
12 - x = 6
x = 6
A charge of 6e⁻ is required to reduce 2 mole of Cr⁶⁺ to Cr³⁺
Answer:
The answer is surface tension.
Explanation:
The high surface tension helps the paper clip - with much higher density - float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. hope this helps :)
Answer:
5.8 L
Step-by-step explanation:
This looks like a case where we can use the <em>Combined Gas Law</em> to calculate the temperature.
p₁V₁/T₁ = p₂V₂/T₂ Multiply both sides by T₂
p₁V₁T₂/T₁ = p₂V₂ Divide each side by V₂
V₂ = V₁ × p₁/p₂ × T₂/T₁
=====
<em>Data</em>:
p₁ = 5.6 atm
V₁ = 20 L
T₁ = 35 °C = 308.15 K
p₂ = 23 atm
V₂ = ?
T₂ = 95 °C = 368.15 K
=====
<em>Calculation:
</em>
V₂ = 20 × 5.6/23 × 368.15/308.15
V₂ = 20 × 0.243 × 1.19
V₂ = 5.8 L
In balancing nuclear decay types of reaction, the same as balancing a chemical reaction, we use the number and the type of nucleons present for the decay reaction. Regardless of the type of decay, it should be that the total number of nucleons in the shole process should be conserved. For carbon-11, the decay equation would be as follows:
11/6 C --->11/5 B + 0/1β
It is an example of a positron emmision or a positive beta decay. It is a decay for neutron-poor nuclei where a proton is being transformed into a neutron and also emitting a positron that is high in energy.
